﻿/******************************************************************************
 *  Project:		Neddle Community Edition
 *  Filename:		DictionaryExtensions.cs
 *	Created By:     Kristopher Cargile <kristopher@neddle.org>
 *  Date Created:	March 29, 2011
 * ****************************************************************************
 * IMPORTANT GNU LICENSE INFORMATION. DO NOT REMOVE THIS SECTION!
 * 
 * Neddle :: Copyright (c) 2010-2012, Cargile Technology Group, LLC
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 ******************************************************************************/

using System.Collections.Generic;

namespace Neddle
{
    /// <summary>
    /// DictionaryExtensions
    /// </summary>
    public static class DictionaryExtensions
    {
        /// <summary>
        /// Removes all instances of <c>obj</c> from
        /// the dictionary
        /// </summary>
        /// <param name="parm"></param>
        /// <param name="obj"></param>
        public static void RemoveAllInstances<T, TU>(this Dictionary<T, TU> parm, TU obj)
        {
            if (parm == null) return;

            List<T> toRemove = new List<T>();
            foreach (KeyValuePair<T, TU> keyValue in parm)
            {
                if (!Equals(keyValue.Key, default(T)) && Equals(keyValue.Value, obj))
                {
                    toRemove.Add(keyValue.Key);
                }
            }
            foreach (T key in toRemove)
            {
                parm.Remove(key);
            }
        }

        /// <summary>
        /// Determines whether [contains key and value] [the specified parm].
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <typeparam name="TU"></typeparam>
        /// <param name="parm">The parm.</param>
        /// <param name="key">The key.</param>
        /// <returns>
        /// 	<c>true</c> if [contains key and value] [the specified parm]; otherwise, <c>false</c>.
        /// </returns>
        public static bool ContainsKeyAndValue<T, TU>(this Dictionary<T, TU> parm, T key) where TU : class
        {
            return parm != null && parm.ContainsKey(key) && parm[key] != null;
        }

        public static TV GetValueOrNull<TK, TV>(this IDictionary<TK, TV> param, TK key)
        {
            param.CheckNull("param");
            key.CheckNull("key");
            TV result;
            param.TryGetValue(key, out result);
            return result;
        }
    }
}
